The present invention relates to a device for positioning a printed circuit board prior to processing the same in a perforating operation at a predetermined location and clamping the printed circuit board in a normal attitude.
In a conventional perforating device of a printed circuit board, unprocessed circuit boards are stacked in a stock box of a stock means. The topmost circuit board is then picked-up by a chuck of a carrier means and transferred to a positioning means. However, the position of the printed circuit board fed by the positioning means is not accurate, but rather, is at an approximate location. Therefore, after accurately positioning the board by the positioning means in conformity with a predetermined standard location, the board is transferred to a perforating means while being in the positioned state and predetermined portions of the printed circuit board are perforated by drills of a perforating means.
In a first example of a conventional positioning means, as disclosed in Japanese Patent Laid-Open No. 85285/1982, there are provided two pivotally fixed rollers opposing a first side of a square circuit board and a further pivotally fixed roller opposing a second side which is orthogonal to the first side. Pivotally movable rollers push the circuit board into contact with the respective fixed rollers so as to push the printed circuit board in the X and Y directions to thereby position the printed circuit board at a standard location.
In a second example of a conventional positioning means, as disclosed in Japanese Patent Laid-Open No. 31959/1988, fixing side positioning members are provided in a vertically movable manner, such that two contiguous sides of a printed circuit board can respectively contact the same. In order to bring the two sides of the printed circuit board into contact with the respective fixing side positioning members, a transverse direction positioning device and a longitudinal direction positioning device are provided at locations proximate the two remaining sides of the printed circuit board, and rollers are respectively provided on both of the transverse and longitudinal direction positioning devices. When the printed circuit board is fed on a table, the printed circuit board is moved such that the rollers of the longitudinal and transverse direction positioning devices are guided by guide grooves. Thus, the printed circuit board is moved in the direction of the positioning members on the fixing side, and two sides of the circuit board are brought into contact with the fixing side positioning members, thereby positioning the printed circuit board at a reference location.
However, in both the first and the second conventional examples, fixing side or moving side positioning means (pins or rollers) are installed at an outer periphery of the four sides of the transverse square printed circuit board. Therefore, the space for installation is increased. This results in an inefficient use of space. Further, the location of the positioning means on the moving side must be moved to be adjusted in conformity with various sizes of the printed circuit board which further results in an inefficient use of the space. Still further, cutting chips are scattered in the perforating operation, and if there are guide grooves as in the second conventional example, the chips are piled up in the guide grooves, thereby lowering the accuracy of positioning. In addition, it is necessary to retract the positioning means such that is does not create a hindrance in feeding the board, and normally, the positioning means has a structure in which pins and the like escape to a lower portion of the table. In other words, pins and the like are provided at the lower portion of the table such that they protrude above the table in the positioning operation. Therefore, it is naturally necessary to provide guide grooves having the shape of an elongated opening to make them movable.